Many disorders, e.g., brain disorders and certain types of paralysis, are treated by an electrical stimulus or local drug delivered to specific sites in the brain or the body. One shortcoming of conventional treatment devices and procedures is that conventional treatment devices are large and their placement may cause damage to the patient Another shortcoming of conventional treatment devices and procedures is that the devices are often implanted and must remain connected to the outside world for their control signal or energy supply. Another shortcoming of conventional devices and procedures is that drug delivery to the target tissue may cause trauma to the patient and may not be precisely delivered to the target tissue. Another shortcoming of conventional procedures is that the physical connection to the outside world and the repeated trauma to the patient required by repeated invasion and introduction of foreign objects into the tissue increases the likelihood of infection. Yet another shortcoming of conventional devices and procedures is that they do not provide precise timing of the delivery of the electrical stimulus or drug in response to phenomena happening in, and to stimuli generated by, the tissue or the organ being treated indicating the need for the delivery of such an electrical stimulus or drug.